The transmission of torque on a standard ten-speed bicycle with derailleur gear-shifting only allows for a limited number of fixed gear ratios. Furthermore, these can be changed only by disengaging the driving and driven members, thus requiring a temporary halt to the transmission of torque. These inadequacies are shared by many other transmission systems, such as those in both manual-shift and automatic-shift vehicles. Other inadequacies of some existing systems include significant frictional losses in the transmission of power. An ideal system would have:
(1) a continuously variable "gear ratio;" PA1 (2) a range of "gear ratios" from negative infinity to positive infinity; PA1 (3) the ability to vary the ratio at any time, whether or not torque is being transmitted; and PA1 (4) little or minimal frictional loss in the transmission of power.
The systems herein described approach these ideals much more closely than any transmission of which I am aware.